Safety-indicator



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STATES PATENT ormcn.

LUGIUS J. KNOWLES, OF \VARR-EN, MASSACHUSETTS.

SAFETY-INDICATOR FOR STEAM-BOILERS.

Specification forming part of Letters Patent No. 16,596, dated February 10, 1857; Reissued February 23, 1858, No. 530.

To all whom it may concern:

Be it known that I, LUOIUS J. KNOWLES, of Warren, in the county of IVorcester and State of Massachusetts, have invented a new and useful or Improved Safety-Indicator for Steam-Boilers; and I do hereby declare that the same is fully described and represented in the following specification and the accompanying drawings, of which Figure 1, denotes a front elevation of the same as applied to a boiler or steam generator. Fig. 2, is a rear view of such. Fig. 3, is an end elevation. Fig. 4C, is a horizontal section of the expansion vessel and the stand by which it is supported.

In the drawings, A, exhibits a steam boiler, provided with a pipe, B, for feeding it with water the said pipe being supposed to lead from a pump or other feeding apparatus. On a level with the usual height, at which, the top surface of the water should stand in the boiler, I arrange a horizontal tubular expansion vessel C, the same being made of metal or other suitable material, and composed of a tube closed at both ends, so as to be steam and water tight. Besides the said vessel I usually employ for the purpose of further safety another such, viz, D which I arrange directly underneath it and at a level beyond which it would not be safe for the water in boiler to descend. Each of these long tubular vessels is to be aflixed by one of its ends to a stationary stand E, the other end of the tube being jointed toa lever F. Two of such levers F, are exhibited in the drawings, each having for its fulcrum the pin or projection a or b, by which the expansion vessel C, or D, is fastened to the stand E.

From the above it will be seen, that whenever, either of the tubular vessels 0, D, is expanded, or contracted lengthwise it will turn its lever on the fulcrum thereof. One of the levers may be supposed to connect with or make part of an apparatus for blowing a whistle or sounding or giving an alarm, so that during the expansion of the tube such apparatus may be put in action so as to blow the whistle or sound or give an alarm. The other lever may be connected with or make part of a mechanism or clutch by which a pump or other feeding apparatus may be brought into action so as to force water through the feed pipe B, and into the boiler.

Each vessel C, or D, is to be connected with the boiler by two pipes or conduits, one leading out of the steam space and the other out of the water space of the boiler. In the air ngement of expansion vessels, as shown in the drawings, they are represented as connected together by a pipe G, which is arranged diagonally between them, and has one or more helical bends, 0, one end of the pipe being made to open into one vessel (C,) while the other end opens into the other vessel (D).

The pipe H, leading from the steam space or upper part of the boiler is bent and made to enter the upper vessel, G, as'shown in the drawings, the pipe, I, communicating with the water space of the boiler, being joined to the lower vessel, D, and made to enter the feed pipe B. It is formed with a bend to extend below the feed pipe as shown in Fig. WVhen but one expansion vessel is used, the pipe, I, may lead out of the same, and into the feed pipe or into the boiler.

By arranging the pipe, G, with respect to the vessels, C, D, and providing it with one or more spiral turns or bends, it is enabled to accommodate itself to either the expansion or contraction of the two vessels. Furthermore, by providing the pipe I, with the bend, (Z, the heat of the water, in the boiler will be hindered from passing up the pipe and into the expansion vessel. By entering the said pipe, I, into the feed pipe B, it receives cool water from the pipe instead of hot water from the boiler, the same tending to cause the expansion apparatus to operate to better advantage than it would were the hot Water of the boiler to flow into it.

In the operation of the above described safety apparatus, each of the expansion vessels, C, D, will be full of water so long as the water in the boiler is above its level, because this must. follow from the known laws of gravity and the manner in which the expansion vessels are connected with the boiler. Under these circumstances, the temperature of the expansion vessel, must be equal to or less than that of the water in the boiler. But whenever the level of the top surface of the water in the boiler may fall below the expansion vessel, the steam from the boiler will enter such vessel and take the place of the water and being of a greater temperature than the Water, will so heat the vessel as to cause it to expand lengthwise,

and for the purpose of moving its lever or the apparatus connected with it, for Work ing the pump or for sounding or giving an alarm. While one of the tubes, C, D, may Work a pump, the other may operate an alarm apparatus or Whistle so that in case the pump should become choked the alarm will be sounded or given.

I do not claim arranging and connecting a tubular or elongated vessel, C, With a steam boiler substantially as described in combination With so supporting the said vessel, C, at one end or part of it, and applying to it a lever or other proper means, that it may expand and contract, and operate said lever or means essentially in manner and for the purpose as specified; but

I claim connecting the pipe, I, .With the boiler by means of the feed pipe, B, the same being productive of an advantage as stated.

In testimony whereof I have hereunto set my signature this first day of November, A. D. 1856.

LUCIUS J. KNOXVLE S,

WVitnesses:

M. K. VI-IIPPLE, F P. ELLIOT.

[Fms'r PRINTED 1912.] 

